Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Consider the following relational schema: Doctor(DName,Reg_no) Patient(Pname, Disease) Assigned_To (Pname,Dname) Give expression in both Tuple calculus and Domain calculus for every of the queries:(i) Get the names of patients who are assigned to more than one doctor. (ii) Get the names of doctors who are treating patients with ‘Polio'.
Ans: (i)Tuple Calculus: {p[PName] | p ∈ PATIENT ∧ ∃a1, a2 (a1 ∈ ASSIGNED_TO ∧ a2 ∈ ASSIGNED_TO ∧p[PName] = a1[PName] ∧ a1[PName] = a2[PName] ∧ a1[DName] ≠ a2[DName])} Domain Calculus:{p | ∃p1, d1, p2, d2 (
∈ PATIENT ∧ ∈ ASSIGNED_TO ∧ ∈ASSIGNED_TO ∧ p1 = p2 ∧ d1 ≠ d2)} (ii)Tuple Calculus: {u[Dname] | u ∈ ASSIGNED_TO ∧ ∃t (t ∈ PATIENT ∧ t[Disease] = ‘Polio' ∧t[PName] = u[PName])} Domain Calculus: {d | ∃p1, p2, s2 ( ∈ ASSIGNED_TO ∧ ∈ PATIENT∧ p1 = p2 ∧ s2 = ‘Polio')}
Demonstrate your knowledge of PL/SQL programming by writing and thoroughly testing triggers and stored procedures associated with an e-commerce application that provides security l
We have a buildup of payments that need to be processed. You will need:- To prepare customer account on our site Process payment (you must have working Paypal account to d
Before we talk about the relational model in more detail, let us first define some very basic terms used in this model. Tuple Every row in a table shows a record and is cal
What is bucket overflow and how bucket overflow is handled through Over Flow Chaining or Closed Hashing? Ans: Bucket: unit of storage holding records. Bucket is a disk block
What are the basic objects of the data dictionary? Tables Domains Data elements Structures Foreign Keys
External failure : A failure can also result because of an external cause, such as earthquakes, fire, floods, etc. The database must be duly backed up to avoid troubles occurring d
define attribute inheritance with example?
i want notes on this topic
What is a transaction ? The Transaction is a unit of data processing. For instance, many of the transactions at a bank may be withdrawal or deposit of money; transfer of money f
Higher Normal Forms Is there more normal forms beyond BCNF? Yes, though, these normal forms are not based on the concept of functional dependence. More normalisation is needed if
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd